Like really, this game doesn't reward Pacifists at all and there's almost no point playing a Xenophile.
As a Collectivist Xenophobe you get expanded borders and enslave everything. purge everything, everything is yours. There is literally no point in playing anything besides Collectivist Xenophobes.
As a Fanatic Pacifist you are unable to expand at all. There is literally nothing fun about it because war is the only thing you can do in Stellaris.
Liberate. Vassalize. Integrate.
Rinse, repeat.
For Fanatic Pacifist? Yeah, I agree. But you can easily get past normal one.
Collectivist Xenophobe WAT??? First allows you to enslave&purge anything, second - enslave&purge anything but your own species, so why would anyone need both at the same time?
Xenophobe gives you two unique things on top of limited purging:
a) Border expansion
b) the earliest and cheapest happiness building in the game - Symbol of unity. You can have everyone be off your ethos. And also not rebel while at war.
I am the first to admit that I understimated that as well.
There is currently no peacful gameplay so being pacifist is kinda pointless.
You build up using the pacifist bonus. Then when at war you can survive the offensive war penalty and have the firepower to over take the enemy (using the pacifist building).
With any additional happiness bonus, and you can even stomach swapping the policy to unrestricted entirely.
Just because there is no peaceful gameplay (which is wrong as both posts above show) you can still play as aggresive pacifist who "liberate" everyone. The bonus is kinda strong and my strongest empires have all been pacifistic ones.
This will be somewhat "fixed" in 1.5. Going to war should increase the Militarist atraction to the point, that you might be better off just letting that pacifism be.
From my own experiences and reading those of others it seems that all combinations of ethics are valid and have their own strengths. You can win with any of them to be honest. Just pick what best suits your playing style or how you want to role play any given race, be aware of the pluses and minuses for the selection and play smart.
They are intended to be equal. But hat does not work out 100%. Ethics divergence will win or loose the game. You can either:
Counter it - Collectivsit Techs, Fanatic Spiritualist, Conformists.
Ignore it - Fanatic Individualist, with some extra happiness (Xenophobe or Pacifist) and Deviants.
This will be solved with Banks, with everyone getting faction atraction
All of them have some way to go about agressiv conquest with the right Ethos/Happiness buildings. If you got those buildings, wich is random and often really hard to get (you need a specific specialist; sometimes 2).
I hope banks moves them to Traditions, that would make them much more expectable.